About Drupal Distributions
Distributions provide site features and functions for a specific type of site as a single download containing Drupal core, contributed modules, themes, and pre-defined configuration. They make it possible to quickly set up a complex, use-specific site in fewer steps than if installing and configuring elements individually.
Drupal 8 Distribution Development and Devops Workflow (video from BadCamp 2016).
Distributions and Install Profiles: The Challenge and the Glory (video, DrupalCon Vienna 2017).